Characteristics of the chemical element germanium. Organic germanium and its use in medicine

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Organic germanium and its application in medicine. organic germanium. Discovery history.

Suponenko A. N.
K. x. PhD, General Director of Germatsentr LLC

The chemist Winkler, having discovered in 1886 a new element of the periodic table germanium in silver ore, did not suspect what attention this element would attract from medical scientists in the 20th century.

For medical needs, germanium was the first to be used most widely in Japan. Tests of various organogermanium compounds in animal experiments and in human clinical trials have shown that they positively affect the human body to varying degrees. The breakthrough came in 1967, when Dr. K. Asai discovered that organic germanium, the method of synthesis of which was previously developed in our country, has a wide spectrum of biological activity.

Among the biological properties of organic germanium, its abilities can be noted:

ensure the transfer of oxygen in the tissues of the body;

increase the immune status of the body;

exhibit antitumor activity

Thus, Japanese scientists created the first drug containing organic germanium "Germanium - 132", which is used to correct the immune status in various human diseases.

In Russia, the biological effect of germanium has been studied for a long time, but the creation of the first Russian drug "Germavit" became possible only in 2000, when Russian businessmen began to invest in the development of science and, in particular, medicine, realizing that the health of the nation requires the closest attention, and its strengthening is the most important social task of our time.

Where is germanium found?

It should be noted that in the process of geochemical evolution of the earth's crust, a significant amount of germanium was washed out from most of the land surface into the oceans, therefore, at present, the amount of this trace element contained in the soil is extremely insignificant.

Among the few plants capable of absorbing germanium and its compounds from the soil, the leader is ginseng (up to 0.2%), which is widely used in Tibetan medicine. Germanium also contains garlic, camphor and aloe, traditionally used for the prevention and treatment of various human diseases. In vegetable raw materials, organic germanium is in the form of carboxyethyl semioxide. At present, germanium organic compounds, sesquioxanes with a pyrimidine fragment, have been synthesized. This compound is structurally close to the naturally occurring germanium compound found in ginseng root biomass.

Germanium is a rare trace element present in many foods, but in microscopic doses.

An estimate of the amount of germanium in the diet, carried out by analyzing 125 types of food products, showed that 1.5 mg of germanium is ingested daily with food. In 1 g of raw foods, it usually contains 0.1 - 1.0 mcg. This trace element is found in tomato juice, beans, milk, salmon. However, to meet the daily needs of the body in germanium, it is necessary to drink, for example, up to 10 liters of tomato juice per day or eat up to 5 kg of salmon, which is unrealistic due to the physical capabilities of the human body. In addition, the prices for these products make it impossible for the majority of the population of our country to regularly use them.

The territory of our country is too vast and on 95% of its territory the lack of germanium is from 80 to 90% of the required norm, so the question arose of creating a germanium-containing drug.

The distribution of organic germanium in the body and the mechanisms of its effects on the human body.

In experiments determining the distribution of organic germanium in the body 1.5 hours after its oral administration, the following results were obtained: a large amount of organic germanium is found in the stomach, small intestine, bone marrow, spleen, and blood. Moreover, its high content in the stomach and intestines shows that the process of its absorption into the blood has a prolonged effect.

The high content of organic germanium in the blood allowed Dr. Asai to put forward the following theory of the mechanism of its action in the human body. It is assumed that organic germanium in the blood behaves similarly to hemoglobin, which also carries a negative charge and, like hemoglobin, participates in the process of oxygen transfer in body tissues. This prevents the development of oxygen deficiency (hypoxia) at the tissue level. Organic germanium prevents the development of so-called blood hypoxia, which occurs with a decrease in the amount of hemoglobin capable of attaching oxygen (a decrease in the oxygen capacity of the blood), and develops with blood loss, carbon monoxide poisoning, and radiation exposure. The most sensitive to oxygen deficiency are the central nervous system, the heart muscle, the tissues of the kidneys, and the liver.

As a result of the experiments, it was also found that organic germanium promotes the induction of gamma interferons, which suppress the reproduction of rapidly dividing cells and activate specific cells (T-killers). The main areas of action of interferons at the body level are antiviral and antitumor protection, immunomodulatory and radioprotective functions of the lymphatic system.

In the process of studying pathological tissues and tissues with primary signs of disease, it was found that they are always characterized by a lack of oxygen and the presence of positively charged hydrogen radicals H + . H + ions have an extremely negative effect on the cells of the human body, up to their death. Oxygen ions, having the ability to combine with hydrogen ions, make it possible to selectively and locally compensate for damage to cells and tissues caused by hydrogen ions. The action of germanium on hydrogen ions is due to its organic form - the form of sesquioxide.

Unbound hydrogen is very active, therefore it easily interacts with oxygen atoms found in germanium sesquioxides. The guarantee of the normal functioning of all body systems should be the unimpeded transport of oxygen in the tissues. Organic germanium has a pronounced ability to deliver oxygen to any point in the body and ensure its interaction with hydrogen ions. Thus, the action of organic germanium in its interaction with H + ions is based on the dehydration reaction (the splitting off of hydrogen from organic compounds), and the oxygen participating in this reaction can be compared to a “vacuum cleaner” that cleanses the body of positively charged hydrogen ions, organic germanium - with a kind of "Chizhevsky's internal chandelier".

Please note that germanium is taken by us in any quantity and form, incl. the form of scrap. You can sell germanium by calling the telephone number in Moscow indicated above.

Germanium is a brittle, silvery-white semimetal discovered in 1886. This mineral is not found in its pure form. It is found in silicates, iron and sulfide ores. Some of its compounds are toxic. Germanium was widely used in the electrical industry, where its semiconductor properties came in handy. It is indispensable in the production of infrared and fiber optics.

What are the properties of germanium

This mineral has a melting point of 938.25 degrees Celsius. The indicators of its heat capacity still cannot be explained by scientists, which makes it indispensable in many areas. Germanium has the ability to increase its density when melted. It has excellent electrical properties, which makes it an excellent indirect-gap semiconductor.

If we talk about the chemical properties of this semimetal, it should be noted that it is resistant to acids and alkalis, water and air. Germanium dissolves in a solution of hydrogen peroxide and aqua regia.

mining germanium

Now a limited amount of this semi-metal is mined. Its deposits are much smaller compared to those of bismuth, antimony, and silver.

Due to the fact that the proportion of the content of this mineral in the earth's crust is quite small, it forms its own minerals due to the introduction of other metals into the crystal lattices. The highest content of germanium is observed in sphalerite, pyrargyrite, sulfanite, in non-ferrous and iron ores. It occurs, but much less frequently, in oil and coal deposits.

Use of germanium

Despite the fact that germanium was discovered quite a long time ago, it began to be used in industry about 80 years ago. Semi-metal was first used in military production for the manufacture of some electronic devices. In this case, it found use as diodes. Now the situation has changed somewhat.

The most popular areas of application of germanium include:

• optics production. Semimetal has become indispensable in the manufacture of optical elements, which include optical windows of sensors, prisms, and lenses. Here, the transparency properties of germanium in the infrared region came in handy. Semimetal is used in the production of optics for thermal imaging cameras, fire systems, night vision devices;
• production of radio electronics. In this area, semi-metal was used in the manufacture of diodes and transistors. However, in the 1970s, germanium devices were replaced by silicon ones, since silicon made it possible to significantly improve the technical and operational characteristics of manufactured products. Increased resistance to temperature effects. In addition, germanium devices emitted a lot of noise during operation.

The current situation with Germany

Currently, semimetal is used in the production of microwave devices. Telleride germanium has proven itself as a thermoelectric material. Germanium prices are now quite high. One kilogram of metallic germanium costs $1,200.

Buying Germany

Silver gray germanium is rare. The brittle semimetal is distinguished by its semiconductor properties and is widely used to create modern electrical appliances. It is also used to create high-precision optical instruments and radio equipment. Germanium is of great value both in the form of a pure metal and in the form of dioxide.

The Goldform company specializes in the purchase of germanium, various scrap metal, and radio components. We offer assistance with the assessment of the material, with transportation. You can mail germanium and get your money back in full.

In 1870 D.I. Mendeleev, on the basis of the periodic law, predicted the still undiscovered element of group IV, calling it ekasilicium, and described its main properties. In 1886, the German chemist Clemens Winkler, during a chemical analysis of the mineral argyrodite, discovered this chemical element. Initially, Winkler wanted to name the new element "neptunium", but this name had already been given to one of the proposed elements, so the element was named after the scientist's homeland - Germany.

Being in nature, getting:

Germanium is found in sulfide ores, iron ore, and is found in almost all silicates. The main minerals containing germanium: argyrodite Ag 8 GeS 6, confieldite Ag 8 (Sn,Ce)S 6, stottite FeGe(OH) 6, germanite Cu 3 (Ge,Fe,Ga)(S,As) 4, rhenierite Cu 3 ( Fe,Ge,Zn)(S,As) 4 .
As a result of complex and time-consuming operations for enrichment of ore and its concentration, germanium is isolated in the form of GeO 2 oxide, which is reduced with hydrogen at 600°C to a simple substance.
GeO 2 + 2H 2 \u003d Ge + 2H 2 O
Germanium is purified by zone melting, which makes it one of the most chemically pure materials.

Physical properties:

Gray-white solid with a metallic luster (mp 938°C, bp 2830°C)

Chemical properties:

Under normal conditions, germanium is resistant to air and water, alkalis and acids, it dissolves in aqua regia and in an alkaline solution of hydrogen peroxide. The oxidation states of germanium in its compounds: 2, 4.

The most important connections:

Germanium(II) oxide, GeO, grey-black, slightly sol. in-in, when heated, it disproportionates: 2GeO \u003d Ge + GeO 2
Germanium(II) hydroxide Ge(OH) 2 , red-orange. crystal,
germanium(II) iodide, GeI 2 , yellow cr., sol. in water, hydrol. bye.
Germanium(II) hydride, GeH 2 , tv. white por., easily oxidized. and decay.

Germanium(IV) oxide, GeO 2 , white crystals, amphoteric, obtained by hydrolysis of chloride, sulfide, germanium hydride, or by the reaction of germanium with nitric acid.
Germanium(IV) hydroxide, (germanic acid), H 2 GeO 3 , weak. unst. biaxial to-ta, germanate salts, for example. sodium germanate, Na 2 GeO 3 , white crystal, sol. in water; hygroscopic. There are also Na 2 hexahydroxogermanates (ortho-germanates), and polygermanates
Germanium(IV) sulfate, Ge(SO 4) 2 , colorless. cr., hydrolyzed by water to GeO 2, obtained by heating germanium (IV) chloride with sulfuric anhydride at 160 ° C: GeCl 4 + 4SO 3 \u003d Ge (SO 4) 2 + 2SO 2 + 2Cl 2
Germanium(IV) halides, fluoride GeF 4 - bests. gas, raw hydrol., reacts with HF, forming H 2 - germanofluoric acid: GeF 4 + 2HF \u003d H 2,
chloride GeCl 4 , colorless. liquid, hydr., bromide GeBr 4 , ser. cr. or colorless. liquid, sol. in org. conn.,
iodide GeI 4, yellow-orange. cr., slow. hydr., sol. in org. conn.
Germanium(IV) sulfide, GeS 2 , white kr., poorly sol. in water, hydrol., reacts with alkalis:
3GeS 2 + 6NaOH = Na 2 GeO 3 + 2Na 2 GeS 3 + 3H 2 O, forming germanates and thiogermanates.
Germanium(IV) hydride, "german", GeH 4 , colorless gas, organic derivatives of tetramethylgermane Ge(CH 3) 4 , tetraethylgermane Ge(C 2 H 5) 4 - colorless. liquids.

Application:

The most important semiconductor material, the main areas of application: optics, radio electronics, nuclear physics.

Germanium compounds are slightly toxic. Germanium is a microelement that in the human body increases the efficiency of the body's immune system, fights cancer, and reduces pain. It is also noted that germanium promotes the transfer of oxygen to the tissues of the body and is a powerful antioxidant - a blocker of free radicals in the body.
The daily requirement of the human body is 0.4–1.5 mg.
Garlic is the champion in germanium content among food products (750 micrograms of germanium per 1 g of dry mass of garlic cloves).

The material was prepared by students of the Institute of Physics and Chemistry of Tyumen State University
Demchenko Yu.V., Bornovolokova A.A.
Sources:
Germanium//Wikipedia./ URL: http://ru.wikipedia.org/?oldid=63504262 (date of access: 06/13/2014).
Germanium//Allmetals.ru/URL: http://www.allmetals.ru/metals/germanium/ (date of access: 06/13/2014).

Germanium is a chemical element with atomic number 32 in the periodic system, denoted by the symbol Ge (Ger. Germanium).

The history of the discovery of germanium

The existence of the element ekasilicium, an analogue of silicon, was predicted by D.I. Mendeleev back in 1871. And in 1886, one of the professors of the Freiberg Mining Academy discovered a new silver mineral - argyrodite. This mineral was then given to the professor of technical chemistry Clemens Winkler for a complete analysis.

This was not done by chance: 48-year-old Winkler was considered the best analyst of the academy.

Quite quickly, he found out that silver in the mineral is 74.72%, sulfur - 17.13, mercury - 0.31, ferrous oxide - 0.66, zinc oxide - 0.22%. And almost 7% of the weight of the new mineral was accounted for by some incomprehensible element, most likely still unknown. Winkler singled out the unidentified component of the argyrodite, studied its properties and realized that he had indeed found a new element - the explication predicted by Mendeleev. This is a brief history of the element with atomic number 32.

However, it would be wrong to think that Winkler's work went smoothly, without a hitch, without a hitch. Here is what Mendeleev writes about this in the supplements to the eighth chapter of Fundamentals of Chemistry: “At first (February 1886), the lack of material, the absence of a spectrum in the burner flame and the solubility of many germanium compounds made Winkler’s research difficult ...” Pay attention to the “lack of spectrum in the flame. How so? Indeed, in 1886 the method of spectral analysis already existed; Rubidium, cesium, thallium, indium have already been discovered on Earth by this method, and helium on the Sun. Scientists knew for sure that each chemical element has a completely individual spectrum, and suddenly there is no spectrum!

The explanation came later. Germanium has characteristic spectral lines - with a wavelength of 2651.18, 3039.06 Ǻ and a few more. But they all lie in the invisible ultraviolet part of the spectrum, and it can be considered fortunate that Winkler's adherence to traditional methods of analysis - they led to success.

Winkler's method for isolating germanium is similar to one of the current industrial methods for obtaining element No. 32. First, the germanium contained in the argarite was converted into dioxide, and then this white powder was heated to 600...700°C in a hydrogen atmosphere. The reaction is obvious: GeO 2 + 2H 2 → Ge + 2H 2 O.

Thus, relatively pure germanium was obtained for the first time. Winkler initially intended to name the new element neptunium, after the planet Neptune. (Like element #32, this planet was predicted before it was discovered.) But then it turned out that such a name had previously been assigned to one falsely discovered element, and, not wanting to compromise his discovery, Winkler abandoned his first intention. He did not accept the proposal to call the new element angular, i.e. “angular, controversial” (and this discovery really caused a lot of controversy). True, the French chemist Rayon, who put forward such an idea, later said that his proposal was nothing more than a joke. Winkler named the new element germanium after his country, and the name stuck.

It should be noted that in the process of geochemical evolution of the earth's crust, a significant amount of germanium was washed out from most of the land surface into the oceans, therefore, at present, the amount of this trace element contained in the soil is extremely insignificant.

The total content of germanium in the earth's crust is 7 × 10 −4% by mass, that is, more than, for example, antimony, silver, bismuth. Germanium, due to its insignificant content in the earth's crust and geochemical affinity with some widespread elements, exhibits a limited ability to form its own minerals, dispersing in the lattices of other minerals. Therefore, germanium's own minerals are extremely rare. Almost all of them are sulfosalts: germanite Cu 2 (Cu, Fe, Ge, Zn) 2 (S, As) 4 (6 - 10% Ge), argyrodite Ag 8 GeS 6 (3.6 - 7% Ge), confildite Ag 8 (Sn, Ge) S 6 (up to 2% Ge), etc. The bulk of germanium is dispersed in the earth's crust in a large number of rocks and minerals. So, for example, in some sphalerites, the content of germanium reaches kilograms per ton, in enargites up to 5 kg/t, in pyrargyrite up to 10 kg/t, in sulvanite and frankeite 1 kg/t, in other sulfides and silicates - hundreds and tens of g/t. t. Germanium is concentrated in deposits of many metals - in sulfide ores of non-ferrous metals, in iron ores, in some oxide minerals (chromite, magnetite, rutile, etc.), in granites, diabases and basalts. In addition, germanium is present in almost all silicates, in some deposits of coal and oil.

Germanium is obtained mainly from by-products of processing non-ferrous metal ores (zinc blende, zinc-copper-lead polymetallic concentrates) containing 0.001-0.1% Germany. Ash from coal combustion, dust from gas generators and waste from coke plants are also used as raw materials. Initially, germanium concentrate (2-10% Germany) is obtained from the listed sources in various ways, depending on the composition of the raw material. The extraction of germanium from concentrate usually involves the following steps:

1) chlorination of the concentrate with hydrochloric acid, its mixture with chlorine in an aqueous medium or other chlorinating agents to obtain technical GeCl 4 . To purify GeCl 4, rectification and extraction of impurities with concentrated HCl are used.

2) Hydrolysis of GeCl 4 and calcination of hydrolysis products to obtain GeO 2 .

3) Reduction of GeO 2 with hydrogen or ammonia to metal. To isolate very pure germanium, which is used in semiconductor devices, metal is melted by zone. Single-crystal germanium, necessary for the semiconductor industry, is usually obtained by zone melting or by the Czochralski method.

GeO 2 + 4H 2 \u003d Ge + 2H 2 O

Semiconductor purity germanium with an impurity content of 10 -3 -10 -4% is obtained by zone melting, crystallization or thermolysis of the volatile GeH 4 monogermane:

GeH 4 \u003d Ge + 2H 2,

which is formed during the decomposition of compounds of active metals with Ge - germanides by acids:

Mg 2 Ge + 4HCl \u003d GeH 4 - + 2MgCl 2

Germanium occurs as an admixture in polymetallic, nickel, and tungsten ores, as well as in silicates. As a result of complex and time-consuming operations for the enrichment of ore and its concentration, germanium is isolated in the form of GeO 2 oxide, which is reduced with hydrogen at 600 ° C to a simple substance:

GeO 2 + 2H 2 \u003d Ge + 2H 2 O.

Purification and growth of germanium single crystals is carried out by zone melting.

Pure germanium dioxide was obtained for the first time in the USSR in early 1941. It was used to make germanium glass with a very high refractive index. Research on element No. 32 and methods for its possible production resumed after the war, in 1947. Now germanium was then of interest to Soviet scientists precisely as a semiconductor.

In appearance, germanium is easily confused with silicon.

Germanium crystallizes in a diamond-type cubic structure, unit cell parameter a = 5.6575Å.

This element is not as strong as titanium or tungsten. The density of solid Germanium is 5.327 g/cm 3 (25°C); liquid 5.557 (1000°C); t pl 937.5°C; bp about 2700°C; thermal conductivity coefficient ~60 W/(m K), or 0.14 cal/(cm sec deg) at 25°C.

Germanium is almost as brittle as glass and can behave accordingly. Even at ordinary temperature, but above 550 ° C, it is amenable to plastic deformation. Hardness Germany on a mineralogical scale 6-6,5; compressibility coefficient (in the pressure range 0-120 Gn/m 2 , or 0-12000 kgf/mm 2) 1.4 10 -7 m 2 /mn (1.4 10 -6 cm 2 /kgf); surface tension 0.6 N/m (600 dynes/cm). Germanium is a typical semiconductor with a band gap of 1.104 10 -19 J or 0.69 eV (25°C); electrical resistivity high purity Germany 0.60 ohm-m (60 ohm-cm) at 25°C; the mobility of electrons is 3900 and the mobility of holes is 1900 cm 2 /v sec (25 ° C) (with an impurity content of less than 10 -8%).

All "unusual" modifications of crystalline germanium are superior to Ge-I and electrical conductivity. The mention of this particular property is not accidental: the value of electrical conductivity (or reciprocal value - resistivity) for a semiconductor element is especially important.

In chemical compounds, germanium usually exhibits valences of 4 or 2. Compounds with a valence of 4 are more stable. Under normal conditions, it is resistant to air and water, alkalis and acids, soluble in aqua regia and in an alkaline solution of hydrogen peroxide. Germanium alloys and glasses based on germanium dioxide are used.

In chemical compounds, germanium usually exhibits valences of 2 and 4, with compounds of 4-valent germanium being more stable. At room temperature, germanium is resistant to air, water, alkali solutions, and dilute hydrochloric and sulfuric acids, but is easily soluble in aqua regia and in an alkaline solution of hydrogen peroxide. Nitric acid slowly oxidizes. When heated in air to 500-700°C, germanium is oxidized to GeO and GeO 2 oxides. Germany oxide (IV) - white powder with t pl 1116°C; solubility in water 4.3 g/l (20°C). According to its chemical properties, it is amphoteric, soluble in alkalis and with difficulty in mineral acids. It is obtained by calcining the hydrated precipitate (GeO 3 nH 2 O) released during the hydrolysis of GeCl 4 tetrachloride. Fusion of GeO 2 with other oxides can be obtained derivatives of germanic acid - metal germanates (Li 2 GeO 3 , Na 2 GeO 3 and others) - solids with high melting points.

When germanium reacts with halogens, the corresponding tetrahalides are formed. The reaction proceeds most easily with fluorine and chlorine (already at room temperature), then with bromine (weak heating) and iodine (at 700-800°C in the presence of CO). One of the most important compounds Germany GeCl 4 tetrachloride is a colorless liquid; t pl -49.5°C; bp 83.1°C; density 1.84 g/cm 3 (20°C). Water strongly hydrolyzes with the release of a precipitate of hydrated oxide (IV). It is obtained by chlorination of metallic Germany or by the interaction of GeO 2 with concentrated HCl. Also known are Germany dihalides of the general formula GeX 2 , GeCl monochloride, Ge 2 Cl 6 hexachlorodigermane, and Germany oxychlorides (for example, CeOCl 2).

Sulfur reacts vigorously with Germany at 900-1000°C to form GeS 2 disulfide, a white solid, mp 825°C. GeS monosulfide and similar compounds of Germany with selenium and tellurium, which are semiconductors, are also described. Hydrogen slightly reacts with germanium at 1000-1100°C to form germine (GeH) X, an unstable and easily volatile compound. By reacting germanides with dilute hydrochloric acid, germanohydrogens of the series Ge n H 2n+2 up to Ge 9 H 20 can be obtained. Germylene composition GeH 2 is also known. Germanium does not directly react with nitrogen, however, there is Ge 3 N 4 nitride, which is obtained by the action of ammonia on Germanium at 700-800°C. Germanium does not interact with carbon. Germanium forms compounds with many metals - germanides.

Numerous complex compounds of germany are known, which are becoming increasingly important both in the analytical chemistry of germanium and in the processes of its preparation. Germanium forms complex compounds with organic hydroxyl-containing molecules (polyhydric alcohols, polybasic acids, and others). Heteropolyacids Germany were obtained. As well as for other elements of group IV, Germany is characterized by the formation of organometallic compounds, an example of which is tetraethylgermane (C 2 H 5) 4 Ge 3.

Germanium(II) hydride GeH 2 . White unstable powder (in air or in oxygen it decomposes with an explosion). Reacts with alkalis and bromine.

Germanium (II) monohydride polymer (polygermine) (GeH 2) n . Brownish black powder. Poorly soluble in water, instantly decomposes in air and explodes when heated to 160 ° C in a vacuum or in an inert gas atmosphere. Formed during the electrolysis of sodium germanide NaGe.

Germanium(II) oxide GeO. Black crystals with basic properties. Decomposes at 500°C into GeO 2 and Ge. Slowly oxidizes in water. Slightly soluble in hydrochloric acid. Shows restorative properties. Obtained by the action of CO 2 on metallic germanium, heated to 700-900 ° C, alkalis - on germanium (II) chloride, by calcining Ge (OH) 2 or by reducing GeO 2.

Germanium hydroxide (II) Ge (OH) 2. Red-orange crystals. When heated, it turns into GeO. Shows amphoteric character. Obtained by treatment of germanium (II) salts with alkalis and hydrolysis of germanium (II) salts.

Germanium(II) fluoride GeF 2 . Colorless hygroscopic crystals, t pl =111°C. Obtained by the action of GeF 4 vapors on germanium metal when heated.

Germanium (II) chloride GeCl 2 . Colorless crystals. t pl \u003d 76.4 ° C, t bp \u003d 450 ° C. At 460°С, it decomposes into GeCl 4 and metallic germanium. Hydrolyzed by water, slightly soluble in alcohol. Obtained by the action of GeCl 4 vapors on germanium metal when heated.

Germanium (II) bromide GeBr 2. Transparent needle crystals. t pl \u003d 122 ° C. Hydrolyzes with water. Slightly soluble in benzene. Soluble in alcohol, acetone. Obtained by the interaction of germanium (II) hydroxide with hydrobromic acid. When heated, it disproportionates into metallic germanium and germanium (IV) bromide.

Germanium (II) iodide GeI 2 . Yellow hexagonal plates, diamagnetic. t pl =460 about C. Slightly soluble in chloroform and carbon tetrachloride. When heated above 210°C, it decomposes into metallic germanium and germanium tetraiodide. Obtained by the reduction of germanium (II) iodide with hypophosphoric acid or by thermal decomposition of germanium tetraiodide.

Germanium(II) sulfide GeS. Received by dry way - greyish-black brilliant rhombic opaque crystals. t pl \u003d 615 ° C, density is 4.01 g / cm 3. Slightly soluble in water and ammonia. Soluble in potassium hydroxide. Received wet - red-brown amorphous precipitate, the density is 3.31 g/cm 3 . Soluble in mineral acids and ammonium polysulfide. Obtained by heating germanium with sulfur or passing hydrogen sulfide through a germanium (II) salt solution.

Germanium(IV) hydride GeH 4 . Colorless gas (density is 3.43 g/cm 3 ). It is poisonous, smells very unpleasant, boils at -88 o C, melts at about -166 o C, thermally dissociates above 280 o C. Passing GeH 4 through a heated tube, a shiny mirror of metallic germanium is obtained on its walls. Obtained by the action of LiAlH 4 on germanium (IV) chloride in ether or by treating a solution of germanium (IV) chloride with zinc and sulfuric acid.

Germanium oxide (IV) GeO 2. It exists in the form of two crystalline modifications (hexagonal with a density of 4.703 g / cm 3 and tetrahedral with a density of 6.24 g / cm 3). Both are air resistant. Slightly soluble in water. t pl \u003d 1116 ° C, t kip \u003d 1200 ° C. Shows amphoteric character. It is reduced by aluminum, magnesium, carbon to metallic germanium when heated. Obtained by synthesis from elements, calcination of germanium salts with volatile acids, oxidation of sulfides, hydrolysis of germanium tetrahalides, treatment of alkali metal germanites with acids, metallic germanium with concentrated sulfuric or nitric acids.

Germanium (IV) fluoride GeF 4 . A colorless gas that smokes in air. t pl \u003d -15 about C, t kip \u003d -37 ° C. Hydrolyzes with water. Obtained by decomposition of barium tetrafluorogermanate.

Germanium (IV) chloride GeCl 4 . Colorless liquid. t pl \u003d -50 o C, t kip \u003d 86 o C, density is 1.874 g / cm 3. Hydrolyzed by water, soluble in alcohol, ether, carbon disulfide, carbon tetrachloride. Obtained by heating germanium with chlorine and passing hydrogen chloride through a suspension of germanium oxide (IV).

Germanium (IV) bromide GeBr 4 . Octahedral colorless crystals. t pl \u003d 26 o C, t kip \u003d 187 o C, density is 3.13 g / cm 3. Hydrolyzes with water. Soluble in benzene, carbon disulfide. Obtained by passing bromine vapor over heated metallic germanium or by the action of hydrobromic acid on germanium (IV) oxide.

Germanium (IV) iodide GeI 4 . Yellow-orange octahedral crystals, t pl \u003d 146 ° C, t kip \u003d 377 ° C, density is 4.32 g / cm 3. At 445 ° C, it decomposes. Soluble in benzene, carbon disulfide, and hydrolyzed by water. In air, it gradually decomposes into germanium (II) iodide and iodine. Attaches ammonia. Obtained by passing iodine vapor over heated germanium or by the action of hydroiodic acid on germanium (IV) oxide.

Germanium (IV) sulfide GeS 2. White crystalline powder, t pl \u003d 800 ° C, density is 3.03 g / cm 3. Slightly soluble in water and slowly hydrolyzes in it. Soluble in ammonia, ammonium sulfide and alkali metal sulfides. It is obtained by heating germanium (IV) oxide in a stream of sulfur dioxide with sulfur or by passing hydrogen sulfide through a solution of germanium (IV) salt.

Germanium sulfate (IV) Ge (SO 4) 2. Colorless crystals, density is 3.92 g/cm 3 . It decomposes at 200 o C. It is reduced by coal or sulfur to sulfide. Reacts with water and alkali solutions. Obtained by heating germanium (IV) chloride with sulfur oxide (VI).

There are five isotopes found in nature: 70 Ge (20.55% wt.), 72 Ge (27.37%), 73 Ge (7.67), 74 Ge (36.74%), 76 Ge (7.67% ). The first four are stable, the fifth (76 Ge) undergoes double beta decay with a half-life of 1.58×10 21 years. In addition, there are two "long-lived" artificial ones: 68 Ge (half-life 270.8 days) and 71 Ge (half-life 11.26 days).

Application of germanium

Germanium is used in the manufacture of optics. Due to its transparency in the infrared region of the spectrum, metallic ultra-high purity germanium is of strategic importance in the production of optical elements for infrared optics. In radio engineering, germanium transistors and detector diodes have characteristics different from silicon ones, due to the lower pn-junction trigger voltage in germanium - 0.4V versus 0.6V for silicon devices.

For more details, see the article application of germanium.

Germanium is found in animals and plants. Small amounts of germanium have no physiological effect on plants, but are toxic in large amounts. Germanium is non-toxic to molds.

For animals, germanium has low toxicity. Germanium compounds have not been found to have a pharmacological effect. The permissible concentration of germanium and its oxide in the air is 2 mg / m³, that is, the same as for asbestos dust.

Divalent germanium compounds are much more toxic.

In experiments determining the distribution of organic germanium in the body 1.5 hours after its oral administration, the following results were obtained: a large amount of organic germanium is found in the stomach, small intestine, bone marrow, spleen, and blood. Moreover, its high content in the stomach and intestines shows that the process of its absorption into the blood has a prolonged effect.

The high content of organic germanium in the blood allowed Dr. Asai to put forward the following theory of the mechanism of its action in the human body. It is assumed that organic germanium in the blood behaves similarly to hemoglobin, which also carries a negative charge and, like hemoglobin, participates in the process of oxygen transfer in body tissues. This prevents the development of oxygen deficiency (hypoxia) at the tissue level. Organic germanium prevents the development of so-called blood hypoxia, which occurs with a decrease in the amount of hemoglobin capable of attaching oxygen (a decrease in the oxygen capacity of the blood), and develops with blood loss, carbon monoxide poisoning, and radiation exposure. The most sensitive to oxygen deficiency are the central nervous system, the heart muscle, the tissues of the kidneys, and the liver.

As a result of the experiments, it was also found that organic germanium promotes the induction of gamma interferons, which suppress the reproduction of rapidly dividing cells and activate specific cells (T-killers). The main areas of action of interferons at the body level are antiviral and antitumor protection, immunomodulatory and radioprotective functions of the lymphatic system.

In the process of studying pathological tissues and tissues with primary signs of disease, it was found that they are always characterized by a lack of oxygen and the presence of positively charged hydrogen radicals H + . H + ions have an extremely negative effect on the cells of the human body, up to their death. Oxygen ions, having the ability to combine with hydrogen ions, make it possible to selectively and locally compensate for damage to cells and tissues caused by hydrogen ions. The action of germanium on hydrogen ions is due to its organic form - the form of sesquioxide. In preparing the article, materials of Suponenko A.N. were used.

Mini - abstract

"Element Germanium"

Target:

Describe the element Ge

Give a description of the properties of the element Ge

Tell about the application and use of this element

Element history ……….………………………………….……. one

Element properties …..……………………………………..…… 2

Application ……………….….…………………………………….. 3

Health hazard ………..………………………....… 4

Sources ………………………….…………………….…………… 5

From the history of the element..

Ggermanium(lat. Germanium) - a chemical element of group IV, the main subgroup of the periodic system of D.I. Mendeleev, denoted by the symbol Ge, belongs to the family of metals, serial number 32, atomic mass 72.59. It is a gray-white solid with a metallic luster.

The existence and properties of Germany were predicted in 1871 by Mendeleev and named this still unknown element - "Ekasilicon" because of the similarity of its properties with silicon.

In 1886, the German chemist K. Winkler, while examining the mineral, found that some unknown element was present in it, which was not detected by analysis. After hard work, he discovered the salts of a new element and isolated a certain amount of the element itself in its pure form. In the first report of the discovery, Winkler suggested that the new element was analogous to antimony and arsenic. Winkler intended to name the element Neptunium, but that name had already been given to one falsely discovered element. Winkler renamed the element he discovered to germanium (Germanium) in honor of his fatherland. And even Mendeleev, in a letter to Winkler, strongly supported the name of the element.

But until the second half of the 20th century, the practical use of Germany remained very limited. The industrial production of this element arose in connection with the development of semiconductor electronics.

Element PropertiesGe

For medical needs, germanium was the first to be used most widely in Japan. Tests of various organogermanium compounds in animal experiments and in human clinical trials have shown that they positively affect the human body to varying degrees. The breakthrough came in 1967 when Dr. K. Asai discovered that organic germanium has a wide range of biological effects.

Properties:

Carries oxygen in the tissues of the body - germanium in the blood behaves similarly to hemoglobin. It is involved in the process of oxygen transfer to the tissues of the body, which guarantees the normal functioning of all body systems.

stimulates the immune system - germanium in the form of organic compounds promotes the production of gamma-interferons, which inhibit the reproduction of rapidly dividing microbial cells, and activates specific immune cells (T-cells)

antitumor - germanium delays the development of malignant neoplasms and prevents the appearance of metastases, and also has protective properties against radiation exposure.

biocidal (antifungal, antiviral, antibacterial) - germanium organic compounds stimulate the production of interferon - a protective protein produced by the body in response to the introduction of foreign bodies.

Application and Use of the Element Germanium in Life

In industrial practice, germanium is obtained mainly from by-products of the processing of non-ferrous metal ores. Germanium concentrate (2-10% Germany) is obtained in various ways, depending on the composition of the raw material. To isolate very pure germanium, which is used in semiconductor devices, metal is melted by zone. Single-crystal germanium, necessary for the semiconductor industry, is usually obtained by zone melting.

It is one of the most valuable materials in modern semiconductor technology. It is used to make diodes, triodes, crystal detectors, and power rectifiers. Germanium is also used in dosimetric devices and devices that measure the intensity of constant and variable magnetic fields. An important field of application of the element is infrared technology, in particular the production of infrared radiation detectors. Many alloys containing germanium are promising for practical use. For example, glasses based on GeO 2 and other Ge compounds. At room temperature, germanium is resistant to air, water, alkali solutions, and dilute hydrochloric and sulfuric acids, but is easily soluble in aqua regia and in an alkaline solution of hydrogen peroxide. And nitric acid oxidizes slowly.

Germanium alloys, which have high hardness and strength, are used in jewelry and denture technology for precision castings. Germanium is present in nature only in the bound state and never in the free state. The most common germanium-bearing minerals are argyrodite and germanite. Large reserves of germanium minerals are rare, but the element itself is widely found in other minerals, especially in sulfides (most often in zinc sulfides and silicates). Small amounts are also found in different types of hard coal.

World production Germany is 65 kg per year.

health hazard

Occupational health problems can be caused by dust dispersion during loading of germanium concentrate, grinding and loading of dioxide to isolate germanium metal, and loading of powdered germanium for remelting into bars. Other sources of harm to health are heat radiation from tube furnaces and during the process of melting powdered germanium into bars, as well as the formation of carbon monoxide.

Absorbed germanium is rapidly excreted from the body, mainly in the urine. There is little information on the toxicity of inorganic germanium compounds to humans. Germanium tetrachloride is a skin irritant. In clinical trials and other long-term cases of oral administration of cumulative doses up to 16 g of spirogermanium, an organic germanium antitumor drug, or other germanium compounds, neurotoxic and nephrotoxic activity has been noted. Such doses are usually not subjected to production conditions. Animal experiments to determine the effects of germanium and its compounds on the body have shown that the dust of metallic germanium and germanium dioxide, when inhaled in high concentrations, leads to a general deterioration in health (limitation of weight gain). Morphological changes similar to proliferative reactions were found in the lungs of animals, such as thickening of the alveolar sections and hyperplasia of the lymphatic vessels around the bronchi and blood vessels. Germanium dioxide does not irritate the skin, but upon contact with the moist mucous membrane of the eye, it forms germanic acid, which acts as an ocular irritant. Long-term intraperitoneal injections at doses of 10 mg/kg lead to changes in peripheral blood .

The most harmful germanium compounds are germanium hydride and germanium chloride. Hydride can cause acute poisoning. Morphological examinations of organs of animals that died during the acute phase revealed disorders in the circulatory system and degenerative cellular changes in parenchymal organs. Thus, hydride is a multipurpose poison that affects the nervous system and the peripheral circulatory system.

Germanium tetrachloride is a strong respiratory, skin, and eye irritant. Threshold concentration - 13 mg / m 3. At this concentration, it suppresses the pulmonary response at the cellular level in experimental animals. In high concentrations, it leads to irritation of the upper respiratory tract and conjunctivitis, as well as changes in the frequency and rhythm of breathing. Animals that survived acute poisoning developed catarrhal desquamative bronchitis and interstitial pneumonia a few days later. Germanium chloride also has a general toxic effect. Morphological changes were observed in the liver, kidneys and other organs of animals.

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